Cook corn in boiling water until tender, about 2 minutes. Cool and remove from cob. Combine corn, beans, tomatoes, onions, pepper, and cilantro in a bowl.

Mix remaining ingredients in a cup. Pour over corn mixture and toss well. Let sit for 30 minutes at room temperature to combine flavour. Taste and adjust seasoning. Serves 4 as a side dish, especially nice with a BBQ dinner.